The present invention relates to a magnetic storage device. More specifically, the present invention relates to a multilevel magnetic solid state storage device.
Magnetic storage devices are widely used in many applications for storing information. One common storage device is a hard disk drive in which a rotating magnetic disk is used to store information which is written and read using a transducer adjacent to the surface of the disk. Other types of memory are solid state memories which use no moving parts. For example, flash memory stores information in an array of transistors which provide a plurality of memory “cells”. There is ongoing desire to increase the data storage capacity available in memory devices. This can be achieved, for example, by scaling the dimensions of the device smaller. However, it is often difficult to continue size reduction of a device in order to achieve higher storage density. Further, the physical phenomena that are used to operate storage technologies may be difficult to implement as the size is reduced. In general, both hard disk drive devices as well as solid state memory devices are two-dimensional (2D) in nature in which the data bits are stored side by side and the areal density of the device typically dictates total device capacity. For example, disk drives store bits on the surface of a disk and solid state memory is built as a 2D array on the surface of a chip.